Error:
Stopped at D:/projects/xquery/geo test.xq, 1/57:
[XQST0059] Module not found: http://expath.org/ns/geo.

Query:
import module namespace geo = "http://expath.org/ns/geo"; declare namespace gml='http://www.opengis.net/gml'; for $x in db:open('geonames2','country') where index-of(['US'], $x/json/countryCode)>0 return geo:envelope( <gml:LinearRing> <gml:coordinates>($x/west, $x/south), ($x/east, $x/south), ($x/east, $x/north), ($x/west, $x/north), ($x/west, $x/south)</gml:coordinates> </gml:LinearRing> )